Jack housing

ABSTRACT

A casting for a jack stand or the like is disclosed. Formed in the casting is an axially tapered hollow, and spaced around the hollow are a number of ribs which have their tip surfaces oriented generally parallel to the hollow axis. A light weight, low cost, high strength casting is produced which needs relatively little subsequent machining in order to produce a finished jack stand part.

United States Patent [1 1 Graafsma Feb. 18,1975

1 1 JACK HOUSING [75] Inventor: Richard S. Graafsma, Benton Harbor, Mich.

[73] Assignee: Auto Specialties Manufacturing Company, St. Joseph, Mich.

[22] Filed: Aug. 24, 1973 21 App]. No.: 391,237

Int. Cl B66f 13/00 158] Field of Search 254/98, 102, 103,93 H;

[56] References Cited UNITED STATES PATENTS 8/1902 Storrs 254/103 11/1922 Schmick 1,444,447 2/1923 Bate 254/98 2,990,159 6/1961 Haferkorn 254/102 3,047,269 7/1962 Renshaw 254/93 H Primary ExaminerAl Lawrence Smith Assistant Examiner-Robert C. Watson Attorney, Agent, or Firm-Olson, Trexler, Wolters, Bushnell & Fosse, Ltd.

1 71 ABSTRACT A casting for a jack stand or the like is disclosed. Formed in the casting is an axially tapered hollow, and spaced around the hollow are a number of ribs which have their tip surfaces oriented generally parallel to the hollow axis. A light weight, low cost, high strength casting is produced which needs relatively little subsequent machining in order to produce a finished jack stand part.

5 Claims, 4 Drawing Figures ///////////////l r///// l JACK HOUSING BACKGROUND OF THE INVENTION This invention relates generally to jack devices, and more particularly concerns a novel jack stand.

Vehicle jacks are well known as highly useful devices for temporarily lifting a vehicle to change a tire or to permit other activity. More generally, jacks have long been known for their ability to temporarily lift any of a wide variety of heavy weights.

Modern jacks designed for use with automobiles and like vehicles must compete with many such devices in the current commercial marketplace. Successfully marketed jacks are usually low in cost, high in strength, low in weight, and easy to use. Improvements in individual jack parts which contribute to these overall attributes are accordingly important.

It thus is the general object of this invention to provide an improved jack stand of light weight, high strength, and low cost.

More specifically, it is an object of the invention to provide a jack stand formed of light weight material having relatively great structural strength.

It is another object of the invention to provide a jack stand at a low finished cost. A related object is to provide a jack stand casting which requires little machine work, after removal from the casting mold, to produce a finished jack stand part.

It is yet another object of the invention to provide a jack stand which firmly supports an extensible and retractible member such as a jack screw member, and which minimizes relative wobble motion between the stand and extensible member.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the description, like reference numerals refer to like parts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a typical jack device employing or incorporating the novel jack stand member;

FIG. 2 is a top plan view of the jack stand member;

FIG. 3 is a bottom plan view of the jack stand memher; and

FIG. 4 is a sectional view taken substantially in the plane of line 44 in FIG. 2 and showing in further detail the jack stand member and its interior configuration.

DETAILED DESCRIPTION While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Turning first to FIG. 1, there is shown ajack I0 utilizing the novel stand member 11. In general, the jack includes at least one extensible member 12 which can be extended, at least partially, from the stand member 11 by an appropriate mechanism such as the illustrated gear and screw arrangement 13. The stand member 11 is rigidly connected to and supported by a base plate l4.

In accordance with the invention, the stand member 11 is light in weight and low in cost. In the illustrated stand member 11, these objectives are met by forming the stand member 11 by known casting techniques from aluminum or a suitable aluminum-containing alloy. As shown in FIGS. 2-4, the jack stand casting 11 includes a conical, axially tapered hollow 17: This hollow 17 may take the shape, in part, ofa truncated cone of extended height having an imaginary altitude or axis 18; the hollow is further defined by an interior surface 19.

It is a feature of the invention that guide means 21 are integrally cast with the stand 11 to guide the extensible member 12 and to minimize wobble or unsteadiness as the extensible member 12 moves into or out of the stand 11. In the embodiment illustrated, these guide means include ribs 23-27, inclusive to engage the surface of the jack screw member 12.

In accordance with another aspect of the invention, the ribs 2327 are unitarily cast with the housing 11 itself, yet the casting mold core which forms the hollow l7 and ribs 2327 can be relatively easily removed from the solidified casting. Further, the necessity for extensively machining the rib surfaces after casting is eliminated. To this end, the ribs 2327 are oriented substantially parallel to the axis 18 of the hollow 17. Moreover, the ribs 23-27 are of a maximum crosssectional size at their lower ends as illustrated in FIG. 4 to compensate for the cone taper, the exterior or extreme tip surfaces 29 of the ribs 23-27 extending substantially parallel to the cone altitude 18. Still further, the ribs 2327 and their cross-sectional shapes are chosen to be small compared to the cross-sectional size of the hollow 17, and the tips 29 are substantially semicircular in peripheral shape. As shown particularly in FIG. 2, five such ribs are spaced equidistantly about the hollow surface 19 to provide the requisite guiding effects for the extensible and retractible jack member 12.

The lower portion of the casting 11 includes an enlarged hollow portion 30 formed to accommodate the screw mechanism 13 or other devices used to operate the jack. The bottom of the casting 11 includes a'pl anar surface 31 oriented perpendicularly to the hollow axis 18. The bottom surface 31 can be formed by casting techniques, and if necessary, machining operations can be used to prepare the surface for attachment to the jack stand base plate 14. Secondary openings 32 can be formed in the casting to accommodate pinion gears or like mechanisms.

The invention is claimed as follows:

1. A die cast jack stand casting having an elongated axially tapered hollow formed therein defined by a tapered interior wall and open at the divergent end, and guide means for guiding a jack member for extensible and retractible motion relative to the casting, said guide means including a plurality of narrow, inwardly and longitudinally extending ribs integral with and spaced around said interior wall, said ribs presenting jack member engaging guide surfaces diverging from said interior wall and substantially parallel to each other and to the longitudinal axis of said casting, said tapered interior wall being formed for permitting removal of the casting from a die while still presenting said substantially parallel surfaces.

2. A casting according to claim 1 having a planar bottom surface adapted for attachment to a base plate.

3. A casting according to claim 2 wherein the planar bottom surface is oriented perpendicularly to the jack member engaging guide surfaces.

4. A casting according to claim 1 including five ribs spaced equidistantly about the hollow surface to inhibit is integrally formed of aluminum-containing metal. 

1. A die cast jack stand casting having an elongated axially tapered hollow formed therein defined by a tapered interior wall and open at the divergent end, and guide means for guiding a jack member for extensible and retractible motion relative to the casting, said guide means including a plurality of narrow, inwardly and longitudinally extending ribs integral with and spaced around said interior wall, said ribs presenting jack member engaging guide surfaces diverging from said interior wall and substantially parallel to each other and to the longitudinal axis of said casting, said tapered interior wall being formed for permitting removal of the casting from a die while still presenting said substantially parallel surfaces.
 2. A casting according to claim 1 having a planar bottom surface adapted for attachment to a base plate.
 3. A casting according to claim 2 wherein the planar bottom surface is oriented perpendicularly to the jack member engaging guide surfaces.
 4. A casting according to claim 1 including five ribs spaced equidistantly about the hollow surface to inhibit wobbling motion of the jack screw member relative to the casting.
 5. A casting according to claim 1 wherein said casting is integrally formed of aluminum-containing metal. 